1. Field of the Invention
The invention relates to a method for permanently monitoring pressurized piping and line systems, including connected loads, carrying fluid media, with pressure measurements in different modes being carried out downstream of the transfer point between supply device and load connection in order to establish consumption values over predeterminable periods of time and to infer the system state, according to preamble of patent claim 1.
2. Description of the Prior Art
DE 10 2004 016 378 A1 discloses a method and an arrangement for actively monitoring piping. The piping to be monitored carries pressurized fluid media, and loads are connected to the respective piping or piping system.
According to the teaching already known, a continuous check or checks in predetermined cycles is or are carried out with the aid of a differential pressure measurement assuming two sensors, preferably at the transfer point or downstream of the transfer point between supply device and load connection, to determine whether permanent and almost constant consumption is present over a predeterminable period of time, with an abnormal state, for example a leak, being inferred in this case, and an alarm being triggered and/or the downstream piping system being shut-off.
In the arrangement there, a series connection comprising a first pressure sensor, a valve that can be actuated electrically or hydraulically, and a second pressure sensor is provided at the transfer point or downstream of the transfer point between supply device and load connection, with control electronics being connected to the pressure sensors and the valve actuating device in order to provide an error signal in the case of a recognized pressure drop per unit time after a controlled valve shut-off.
Specifically, according to DE 10 2004 016 378 A1, a valve provided at the transfer point or downstream of the transfer point is closed during the leak determination operation so that the piping system located downstream is briefly shut off. In this state, the instantaneously present inlet pressure is established and saved. After this, the pressure drop is determined on the basis of the saved inlet pressure value and the measured outlet pressure, and a check as to whether the determined pressure drop per unit time exceeds a predetermined value is carried out, as a result of which a fault in the piping system can be inferred.
In the tapping operation, the said valve is opened and an acquisition of changes in the pressure differences of the pressure values upstream and downstream of the valve is carried out. In the case of pressure difference values no longer changing over a predetermined period of time, a switch between the mentioned operation modes is carried out. The switch between leak determination operation and tapping operation is permanently undertaken, with the switch being triggered depending on established pressure variations caused by consumer tap points. Generally, the switch between the individual modes is carried out a number of times within an hour.
In the case of operation with loads which intend to continuously remove media for a long time, e.g. for watering the garden, a volume-flow-varying element is used, with this element periodically or stochastically changing the load-dependent through-flow rate.
In the case of the method explained above, the stopping action of the valve and also the evaluation of the pressure conditions of the inlet pressure are disadvantageous for the performance aimed for. In this respect, the method and the associated arrangement must be optimized for each piping structure and for specific valves, that is to say for each demand. Furthermore, stringent requirements are imposed on the impulse behavior of the pressure sensors used.
With regard to known pressure difference measurements with downstream processor-aided pressure evaluation, reference is also made to DE 197 06 564 A1, wherein a shutting-off command is triggered in that case when a predetermined water outflow is exceeded, and there is thus no specific leak determination operation.
DE 198 14 903 C2 discloses a method for preventative shutting-off of a supply line for a medium depending on the consumption habits of the users and pressure measurements in the lines. Specifically, the line pressure in the shut-off pipeline is measured in that case in a shut-down phase and, in the case of a pressure drop in the piping system that is unusual for normal consumption, a fault is signaled. In a refinement, not only the pressure drop, but also a pressure increase over the usual level is intended to be evaluated.
In the case of this solution from the prior art, it is thus necessary to establish pressure conditions which apply to the usual use and consumption, with all such pressure conditions having to be saved as comparison values.